Thousands of tulips are rising to the occasion, just in time for Zoo Blooms at the Cincinnati Zoo & Botanical Garden. They survived what everyone agrees was a long, cold winter.

But long and cold are relative terms. Especially when one considers that the zoo has kept some plant materials in a deep freeze for more than two decades, in conditions so cold it’s hard for the human mind to comprehend.

The CryoBioBank at CREW, the zoo’s Center for Conservation and Research of Endangered Wildlife, contains one of the world’s oldest and most diverse frozen collections of wild plant materials – more than 3,000 samples, including seeds, spores, shoot tips and pollen, many from endangered species. They are preserved in liquid nitrogen at a temperature of minus 196 degrees Celsius, which, on the Fahrenheit scale, is 321 degrees below zero. Full article…